"Its a curious point though - if you could even slightly "rest" your shooting hand so as not to interfere with the shooting of the bow, could this "rested" bow rival a crossbow? Is that the only thing affecting accuracy between the two ? '

Pete: you are operating on some common misconceptions about xbows. Allow me to share some stuff w/ you? There is a gentleman on AT named Jim C that is an archery instructer, holds some recordsI believe, and is a big crossbow supporter. He among other things teaches youngsters and has at times past either owned or been part owner in an archery shop. He conducted some tests by mounting those little red lazer pointers that kids just love to get in trouble at school w/, lol on both vert bows and xbows. The object was to hold the red dot on the bull as long as possible, no shots ever needed fired. The vertswon hands down every time. His results are also verified in the competition scores where the vert exceeds the xbow evey time. W/o preaching to the choir here, in every state that keeps separate stats, the harvest rates percentage wise are nearly equal between the two, hence no net advantage/disadvantage.